What is CVE-2026-12523?

CVE-2026-12523 is a high-severity vulnerability in Cloudflare Quiche. CVSS score: 7.5/10. Published 2026-07-14.

How severe is CVE-2026-12523?

High severity. CVSS v3 base score is 7.5 out of 10.

Vulnerability in Cloudflare Quiche

CVE-2026-12523

Summary Cloudflare quiche's HTTP/3 layer was discovered to be vulnerable to resource exhaustion (i.e., memory) by means of specially crafted HTTP/3 frames. Impact HTTP/3 defines multiple frame types to support HTTP message exchan…

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

Affected products

Cloudflare Quiche — versions 0.1.0

References

cna@cloudflare.com

Frequently asked questions

What is CVE-2026-12523?: CVE-2026-12523 is a high-severity vulnerability in Cloudflare Quiche. CVSS score: 7.5/10. Published 2026-07-14.
How severe is CVE-2026-12523?: High severity. CVSS v3 base score is 7.5 out of 10.